Revisiting the transorbital approach for emergency external ventricular drainage: an anatomical study of relevant parameters and their effect on the effectiveness of using Tubbs' point.

The transorbital approach (TOA) can provide immediate access to the lateral ventricles by piercing the roof of the orbit (ROO) with a spinal needle and without the need of a drill. Reliable external landmarks for the TOA ventriculostomy have been described, however, the necessary spinal needle gauge and other relevant parameters such as the thickness of the ROO have not been evaluated. Nineteen formalin-fixed adult cadaveric heads underwent the TOA. Spinal needles of different gauges were consecutively used in each specimen beginning with the smallest gauge until the ROO was successfully pierced. The thickness of the ROO at the puncture site and around its margins was measured. Other parameters were also measured. The TOA was successfully performed in 14 cases (73.68%), where the most suitable needle gauge was 13 (47.37%), followed by a 10-gauge needle (36.84%). The mean thickness of the ROO at the puncture site, and the mean length of the needle to the puncture site were 1.7 mm (range 0.2-3.4 mm) and 15.5 mm (range 9.2-23.4 mm), respectively. A ROO thickness of greater than 2.0 mm required a 10-gauge needle in seven cases, and in five cases, a 10-gauge needle was not sufficient for piercing the ROO. The presence of hyperostosis frontalis interna (HFI) (21.05%) was related to the failure of this procedure (80%; p < 0.00). Using a 13/10-gauge spinal needle at Tubbs' point for TOA ventriculostomy allowed for external ventricular access in most adult specimens. The presence of HFI can hinder this procedure. These findings are important when TOA ventriculostomy is considered.

Transosseous Veins of the Temporal Bone: Connection Between Middle and Posterior Cranial Fossa Venous Structures.

BACKGROUND: The veins and dural venous sinuses of the skull base are important to understand in terms of imaging findings, diagnoses, and surgery. However, to date and to the best of our knowledge, the transosseous veins of the petrous part of the temporal bone have not been studied. METHODS: Ten latex-injected adult cadaveric specimens (20 sides) were dissected to identify the intraosseous and transosseous veins. The petrous part of the temporal bone was drilled away, and the petrous part of the internal carotid artery and the veins of the middle and posterior cranial fossa adjacent to the petrous part of the temporal bone were exposed. RESULTS: Transosseous veins traveling through the petrous part of the temporal bone were identified on all 20 sides. In general, these were most concentrated near the anterior and posterior parts of the petrous part of the temporal bone. Most traveled more or less vertically from the petrous ridge and related superior petrosal sinus internally through the petrous part of the temporal bone toward the inferior petrosal sinus or horizontally, uniting the veins of the floor of the middle cranial fossa with the veins of the posterior cranial fossa. These transosseous veins connected the veins in the middle cranial fossa with the veins of the posterior cranial fossa. Most (70%) of these transosseous veins were also found to have small connections to the internal carotid venous plexus. CONCLUSIONS: To the best of our knowledge, previous studies have not reported on transosseous veins of the temporal bone or described their anatomy of connecting the veins of the middle and posterior cranial fossae.

Effects of the COVID-19 Pandemic on Operative Volume and Residency Training at Two Academic Neurosurgery Centers in New Orleans.

BACKGROUND: Medical subspecialties including neurosurgery have seen a dramatic shift in operative volume in the wake of the coronavirus disease 2019 (COVID-19) pandemic. The goal of this study was to quantify the effects of the COVID-19 pandemic on operative volume at 2 academic neurosurgery centers in New Orleans, Louisiana, USA from equivalent periods before and during the COVID-19 pandemic. METHODS: A retrospective review was conducted analyzing neurosurgical case records for 2 tertiary academic centers from March to June 2020 and March to June 2019. The records were reviewed for variables including institution and physician coverage, operative volume by month and year, cases per subspecialty, patient demographics, mortality, and morbidity. RESULTS: Comparison of groups showed a 34% reduction in monthly neurosurgical volume per institution during the pandemic compared with earlier time points, including a 77% decrease during April 2020. There was no change in mortality and morbidity across institutions during the pandemic. CONCLUSIONS: The COVID-19 pandemic has had a significant impact on neurosurgical practice and will likely continue to have long-term effects on patients at a time when global gross domestic products decrease and relative health expenditures increase. Clinicians must anticipate and actively prepare for these impacts in the future.

Papillary tumor of the pineal region in pediatric populations: An additional case and systematic review of a rare tumor entity.

Papillary tumors of the pineal region (PTPR) are a rare tumor entity first described in 2003, later codified in the 2007 WHO tumor classification system. PTPRs most commonly occur in the third and fourth decades, with exceedingly rare presentations in pediatric populations. Herein, we present an additional case of a 10-year-old female found to have PTPR in conjunction with Trisomy 21 managed successfully with cerebrospinal fluid diversion and gross total resection (GTR). Three years after resection she has returned to baseline without recurrence. We also performed a comprehensive review of the current literature discussing the diagnosis, treatment, and pathophysiologic correlations in children. Diagnosis and management of PTPRs is a topic that is increasingly garnering attention in the literature given the recent characterization of this tumor entity. However, relatively little is known about the presentation of PTPRs in pediatric populations. In adults, PTPRs have been linked with several chromosomal and genetic abnormalities; however this correlation is limited in pediatric literature. Although GTR is the mainstay for treatment, the application of adult treatment protocols may not be advisable due to age and the developmental changes of the CNS in children.

Symptomatic xanthogranuloma of the lateral ventricle in a pregnant patient treated with delayed resection: A case report and systematic review.

Intracranial xanthogranulomas (XG) are a rare benign histiocytic neoplasm and most often within the choroid. The majority are asymptomatic and are found incidentally on imaging or post-mortem examination or autopsy. We present a case of symptomatic XG in a pregnant patient who underwent a delayed transcortical, transventricular approach for lateral ventricle XG resection following the completion of her pregnancy. Four years post-operatively, the patient is neurologically intact and without recurrence. Our review of the literature showed differences among XG depending on location. The clinical and radiological features of XG are often indistinguishable from tumors arising from the choroid plexus and should be considered as a rare etiology in the differential of newly diagnosed intraventricular lesions.

Pleomorphic Xanthoastrocytoma of the Pineal Region in a Pediatric Patient With Neurofibromatosis Type 1.

Background: Pleomorphic xanthoastrocytoma (PXA) is a rare and often focal glioma that most commonly affects children and young adults. Lesions are preferentially supratentorial and superficial, although infratentorial masses have been described, along with occasional involvement of the leptomeninges. The World Health Organization (WHO) categorizes these tumors as grade II, with surgical resection carrying a favorable prognosis. However, these tumors may undergo malignant degeneration and must be identified for appropriate treatment and prognosis. PXA has been associated with neurofibromatosis type 1 (NF1), although it is not the classic phenotype of NF1. We present a novel report of PXA, atypically located in the pineal region of a patient with a history of NF1. Case Report: A 17-year-old male with a history of NF1 presented with 1 month of bifrontal headaches. Magnetic resonance imaging was significant for a heterogeneous tectal mass, suspicious for a glioma extending to the fourth ventricle and causing displacement of the cerebral aqueduct without obstructive hydrocephalus. Following an infratentorial-supracerebellar approach for tumor resection, histopathology confirmed a low-grade variable neoplasm consistent with PXA. Postoperative imaging confirmed gross total resection with no evidence of recurrence at 9 months postoperatively. Conclusion: To our knowledge, this case is the fifth report of pineal PXA and the first associated with NF1. Because PXA presents similarly to other NF1-related intracranial tumors, careful diagnosis via immunohistochemistry is imperative. Gross tumor resection is usually curative; however, PXA has the propensity to undergo malignant degeneration and may require adjuvant treatment.

Adult Pineal Region Atypical Teratoid Rhabdoid Tumor: A Case for Aggressive Surgical and Chemoradiation Management with Comprehensive Literature Review.

BACKGROUND: Atypical teratoid rhabdoid tumor (ATRT) is a rare, highly malignant central nervous system neoplasm classified as an embryonal grade IV neoplasm by the World Health Organization. ATRT generally occurs in children younger than 3 years, with 85 pathologically confirmed cases reported in adults. It is most commonly supratentorial, with only 9 confirmed adult cases localized to the pineal region. CASE DESCRIPTION: The case is described of a 29-year-old man with a history of chronic migraines and a previously negative computed tomography scan of the head presenting with worsening headaches and new-onset diplopia with upward gaze palsy. Computed tomography and magnetic resonance imaging showed a hemorrhagic pineal mass with extension into the right thalamus. After resection, the immunohistochemical staining and cytogenetic profile proved consistent with ATRT, making it the ninth reported case of pineal ATRT in an adult, which was treated aggressively with good outcome. CONCLUSIONS: Adult ATRT is rare, especially in the pineal region, with only 9 cases reported. Because of the aggressiveness, ATRT must be considered in the differential diagnosis of pineal region lesions because early diagnosis and aggressive treatment are key to prolonged survival.

Coronavirus 2019 (COVID-19)-Associated Encephalopathies and Cerebrovascular Disease: The New Orleans Experience.

BACKGROUND: The coronavirus 2019 (COVID-19) pandemic has had a dramatic impact on health care systems and a variable disease course. Emerging evidence demonstrates that severe acute respiratory syndrome coronavirus 2 is associated with central nervous system disease. We describe central nervous system manifestations in critical patients with COVID-19 at our tertiary center. METHODS: We conducted a single-center retrospective analysis of all actively critical patients with COVID-19 admitted to our tertiary care academic center in New Orleans, Louisiana, on April 22, 2020, with new onset of neurologic disease. Patients were grouped into 1 of 3 categories according to imaging and clinical features; encephalopathy, acute necrotizing encephalopathy, and vasculopathy. RESULTS: A total of 27 of 76 (35.5%) critical patients with COVID-19 met inclusion criteria. Twenty patients (74%) were designated with COVID-19-associated encephalopathy, 2 (7%) with COVID-19-associated acute necrotizing encephalopathy, and 5 (19%) with COVID-19-associated vasculopathy. Sixty-three percent of neurologic findings were demonstrated on computed tomography, 30% on magnetic resonance imaging, and 44% on electroencephalography. Findings most often included ischemic strokes, diffuse hypoattenuation, subcortical parenchymal hemorrhages, and focal hypodensities within deep structures. Magnetic resonance imaging findings included diffuse involvement of deep white matter, the corpus callosum, and the basal ganglia. For patients with large-territory ischemic stroke, all but one displayed irregular proximal focal stenosis of the supraclinoid internal carotid artery. CONCLUSIONS: Analysis of active critical COVID-19 admissions at our revealed a high percentage of patients with new neurologic disease. Although variable, presentations followed 1 of 3 broad categories. A better understanding of the neurologic sequalae and radiographic findings will help clinicians mitigate the impact of this disease.

Neurological Impact of Coronavirus Disease of 2019: Practical Considerations for the Neuroscience Community.

BACKGROUND: The coronavirus disease of 2019 (COVID-19), which is caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has recently been designated a pandemic by the World Health Organization, affecting 2.7 million individuals globally as of April 25, 2020, with more than 187,000 deaths. An increasing body of evidence has supported central nervous system involvement. METHODS: We conducted a review of the reported data for studies concerning COVID-19 pathophysiology, neurological manifestations, and neuroscience provider recommendations and guidelines. RESULTS: Central nervous system manifestations range from vague nonfocal complaints to severe neurological impairment associated with encephalitis. It is unclear whether the neurological dysfunction results from direct viral injury or systemic disease. The virus could affect brainstem pathways that lead to indirect respiratory dysfunction, in addition to direct pulmonary injury. Necessary adaptations in patient management, triage, and diagnosis are evolving in light of the ongoing scientific and clinical findings. CONCLUSIONS: The present review has consolidated the current body of data regarding the neurological impact of coronaviruses, discussed the reported neurological manifestations of COVID-19, and highlighted the recommendations for patient management. Specific recommendations pertaining to clinical practice for neurologists and neurosurgeons have also been provided.

Recurring Primary Xanthomatous Hypophysitis Behaving Like Pituitary Adenoma: Additional Case and Literature Review.

BACKGROUND: Xanthomatous hypophysitis (XH) is the rarest histologic type of primary hypophysitis. It is nonlymphocytic and characterized by an infiltration of the pituitary gland by lipid-laden histiocytes and macrophages. The clinical and radiologic features overlap heavily with pituitary adenomas and are prone to misdiagnosis. We describe a rare case of XH recurrence at 1 year, treated surgically. Moreover, we provide an updated review of the literature to further elucidate useful management and detection strategies. CASE DESCRIPTION: A 45-year-old woman presented with a history of menstrual irregularity for 9 months, amenorrhea, galactorrhea, and headache for 2 months duration. Preoperative endocrinologic studies showed increased prolactin levels. Magnetic resonance imaging of the sella showed a cystic lesion with suprasellar extension suggestive of a pituitary adenoma. The patient underwent transsphenoidal resection, showing a thick yellowish colloidal material. Histopathology showed necrotic tissue with no definitive diagnosis and no identified microorganisms. At 2 months after surgery, prolactin levels and menstrual cycle normalized. At 1 year after surgery, her menstrual cycle again became irregular. Repeat magnetic resonance imaging showed a recurrent mass and a second transsphenoidal resection was undertaken. Repeat histopathology was consistent with XH. The patient is 9 years postoperative and is doing well without evidence of recurrence. CONCLUSIONS: XH presents similarly to nonfunctional adenomas and diagnosis remains difficult without surgical pathology, requiring meticulous immunohistochemistry to prevent misdiagnosis. Thus, XH should be considered as a rare cause in the differential of disease of the sellar region. Management can parallel that of pituitary neoplasm, with a focus on radiosurgery, re-resection, and high-dose steroids.

"Two-Birds-One-Stone" Approach for Treating an Infant with Chiari I Malformation and Hydrocephalus: Is Cerebrospinal Fluid Diversion as Sole Treatment Enough?

BACKGROUND: Chiari I malformation (CIM) is a disorder characterized by caudal displacement of the cerebellar tonsils below the foramen magnum. It is often associated with syringomyelia and occasionally with hydrocephalus. CIM is commonly treated by posterior fossa decompression with or without removal of the posterior arch of C1 and duraplasty, but the treatment for infants with symptomatic CIM is not well established. We present a case of symptomatic CIM in an infant that was successfully treated with a ventriculoperitoneal shunt (VPS) and discuss the importance of the pathophysiology in management decisions. CASE DESCRIPTION: A 6-month-old male with a CIM and a cervicothoracic syrinx presented with stridor, lower cranial nerve dysfunction, and increased tone that worsened with crying. Magnetic resonance imaging studies revealed cerebellar tonsillar displacement extending to the level of C3-C4 with a syrinx extending from C4 to T4. In addition, there was compression of the cervicomedullary junction, fourth ventricular outflow obstruction, and obstructive hydrocephalus. The decision was made to place a ventriculoperitoneal shunt (VPS) instead of performing decompressive surgery as the initial treatment intervention. The infant had significant symptomatic relief at 6-, 9-, and 12-month follow-ups. Postoperative magnetic resonance imaging at 6-month follow-up revealed resolution of the syrinx and ventriculomegaly and ascent of the cerebellar tonsils. CONCLUSIONS: Ventriculoperitoneal shunting alone was successfully used to treat an infant with concurrent CIM, syrinx, and hydrocephalus. This case underscores not only the importance of hydrocephalus as the pathogenesis of CIM in some cases but also the possibility of avoiding the morbidity of decompressive surgery in infants.

Response assessment of meningioma: 1D, 2D, and volumetric criteria for treatment response and tumor progression.

BACKGROUND: Meningiomas are the most common primary brain tumors in adults. Due to their variable growth rates and irregular tumor shapes, response assessment in clinical trials remains challenging and no standard criteria have been defined. We evaluated 1D, 2D, and volume imaging criteria to assess whether a volumetric approach might be a superior surrogate for overall survival (OS). METHODS: In this retrospective multicenter study, we evaluated the clinical and imaging data of 93 patients with recurrent meningiomas treated with pharmacotherapy. One-dimensional (1D), 2D, and volumetric measurements of enhancing tumor on pre- and post-treatment MRI were compared at 6 and 12 months after treatment initiation. Cox proportional hazards models were used to examine the relationship between each imaging criterion and OS. RESULTS: The median age of the patient cohort is 51 years (range 12-88), with 14 World Health Organization (WHO) grade I, 53 WHO grade II, and 26 WHO grade III meningiomas. Volumetric increase of 40% and unidimensional increase by 10 mm at 6 months and 12 months provided the strongest association with overall survival (HR = 2.58 and 3.24 respectively, p<0.01). Setting a volume change threshold above 40% did not correlate with survival. The interobserver agreement of 1D, 2D, and volume criteria is only moderate (kappa = 0.49, 0.46, 0.52, respectively). None of the criteria based on tumor size reduction were associated with OS (P > 0.09). CONCLUSION: Compared with 1D (Response Evaluation Criteria In Solid Tumors 1.1) and 2D (Response Assessment in Neuro-Oncology) approaches, volumetric criteria for tumor progression has a stronger association with OS, although the differences were only modest. The interobserver variability is moderate for all 3 methods. Further validation of these findings in an independent patient cohort is needed.

Rigid Internal Fixation for Traumatic Cranio-Cervical Dissociation in Infants and Young Children.

STUDY DESIGN: Retrospective review. OBJECTIVE: Evaluate radiographic and clinical outcomes for infants and children, who underwent rigid occipito-cervical fixation for traumatic craniocervical dissociation (tCCD). SUMMARY OF BACKGROUND DATA: Traumatic craniocervical dissociation is devastating. Children are at high risk but make up a large number of survivors. Non-rigid fixation has traditionally been favored over screw and rod constructs due to inherent challenges involved with instrumenting the pediatric craniocervical junction. Therefore, outcomes for rigid occipito-cervical instrumentation in infants and young children with tCCD remain uncertain. METHODS: Retrospective review of children who survived tCCD between 2006 and 2016 and underwent rigid occipito-cervical fixation. RESULTS: Fifteen children, from 8 months to 8 years old (mean, 3.8 yr), were either a passenger (n = 11) or a pedestrian (n = 4) in a motor vehicle accident. Seven patients had weakness: five with quadriplegia, one with hemiparesis, and one with bilateral upper extremity paresis. Ten patients had concurrent C1-2 instability. At last follow-up, four patients had improved motor function: one with bilateral upper extremity paresis and one with hemiparesis regained full strength, one with quadriplegia regained function on one side while another regained function in bilateral upper extremities. All underwent rigid posterior occipito-cervical fixation, with two patients requiring additional anterior and posterior fixation at non-contiguous levels. Fourteen patients were stable on flexion-extension x-rays at a mean follow-up of 31 months (9-1 yr or longer, 7-2 yr or longer). There were no cases of deformity, growth disturbance, or subaxial instability. CONCLUSION: Children who survive tCCD may regain function after stabilization. Rigid internal rod and screw fixation in infants and young children safely provided long-term stability. We advocate using C2 translaminar screws to exploit the favorable anatomy of pediatric lamina to minimize the risks of occipitocervical (OC) instrumentation. LEVEL OF EVIDENCE: 4.

Rare Intradural Cervical Nerve Root Metastasis of Follicular Thyroid Carcinoma.

Intradural extramedullary nerve root metastasis is extremely unusual with only a handful of cases reported, and it presents most commonly in the thoracic and lumbosacral regions. We report the first case of metastasis to a ventral cervical nerve root in a patient with low-grade follicular thyroid carcinoma thought to be in remission for several years. Histopathology demonstrated malignant transformation and invasion of the nerve root. This case underscores that any history of malignancy regardless of staging, grading, or remission status should raise the suspicion of metastasis as it can mimic other spine and nerve sheath tumors and represent malignant transformation. Gross total resection can be safely achieved with intraoperative neuromonitoring and result in improved function; however, treatment is likely palliative.

Recurrent Craniocervical Pseudogout: Indications for Surgical Resection, Surveillance Imaging, and Craniocervical Fixation.

BACKGROUND: Calcium pyrophosphate dihydrate (CPPD) crystallization is known to occur in the spine, leading to the development of visible calcification as seen by imaging. Occasionally, the deposition of this material can lead to larger accumulations that are seen as masses in the articular processes, intervertebral discs, and posterior longitudinal ligaments. A particularly significant manifestation of this process is at the craniocervical junction, where symptomatic presentations can arise. CLINICAL PRESENTATION:  A 74-year-old woman presented after several falls from standing, complaining of leg and arm weakness. Imaging revealed a mass arising from the C1-C2 articulation dorsal to the dens, extending to the clivus. The mass compressed the medulla and cervicomedullary junction. INTERVENTION: The patient underwent a left, far lateral craniotomy with C1 laminectomy to approach the cervicomedullary junction. The mass was cyst-like and contained scattered crystals and amorphous material consistent with pseudogout. There were no cells with an elevated Ki-67 index. The patient's symptoms and exam improved at follow-up two months later. However, seven months after surgery, she declined once again and was found to have a recurrence. CONCLUSION: A subtotal resection of pseudogout may lead to recurrence. The recurrence can occur in a rapid fashion. Serial MRIs are indicated following resection. Occipitocervical fusion could reduce the likelihood of recurrence in such cases.

Functional radiography in examination of spondylolisthesis.

OBJECTIVE: Despite the predominant use of standing flexion-extension radiography for quantifying instability in isthmic and degenerative spondylolisthesis, other functional radio-graphic techniques have been presented in the literature. CONCLUSION: The current evidence reported in the literature is insufficient to influence how the results of these other functional radiographic techniques should affect clinical management; however, it does raise doubts regarding the accuracy and reliability of standing flexion-extension radiography in this setting. Based on the currently available evidence and until randomized studies are performed to assess the efficacy of functional radiographic techniques in directing clinical decision making, positioning schemes other than traditional standing flexion-extension may be considered as options in the evaluation of patients with symptomatic isthmic and degenerative spondylolisthesis in which standard flexion-extension radiographs fail to show pathologic instability.